Yes, fish can get 'depressed' in their own way, more noticeable in some species than others. Do they look at old pictures or cry and watch old movies or experience the thoughts or feelings of a depressed human? Not exactly, but some will sulk, not eat much, hang in one spot etc. as obvious 'depression like' behaviors differing from normal. Oddly enough, one study of 'depression' in fish (related to stress and stress hormones) with abnormal chemistry found they responded to antidepressants like prozac -- link
If you're keeping up with the science, there are some antiquated assumptions about fish perception and intelligence we should probably put behind us. Some are still up in the air, as one study concludes one thing and another study something else (do fish feel pain?) but other things appear pretty well antiquated (3 second memory). No, they're not sitting in their tanks contemplating relativity or quantum physics or the meaning of life, but they're not exactly unconscious, mindless robots operating only on autopilot either.
If you're keeping up with the science, there are some antiquated assumptions about fish perception and intelligence we should probably put behind us. Some are still up in the air, as one study concludes one thing and another study something else (do fish feel pain?) but other things appear pretty well antiquated (3 second memory). No, they're not sitting in their tanks contemplating relativity or quantum physics or the meaning of life, but they're not exactly unconscious, mindless robots operating only on autopilot either.
